1, Laser working medium
The laser must be produced by selecting a suitable working medium, which can be a normal body, a liquid, a solid or a semiconductor. In this medium, particle number inversion can be achieved to produce the necessary conditions for obtaining a laser. As the core of the laser, it consists of activated particles (both metal) and matrix. Its matrix mainly determines the physical and chemical properties of the working substance.
2. Incentive source
In order to cause the population inversion in the working medium, the atomic system must be excited by a certain method to increase the number of particles at the upper level. Generally, gas discharge can be used to excite electrons with kinetic energy to excite medium atoms, which is called electro-excitation; pulsed light sources can also be used to illuminate working medium, called photoexcitation; and thermal excitation, chemical excitation, and so on.
3, Concentrating system
The concentrating cavity has two functions, one is to effectively couple the pump source with the working substance; the other is to determine the distribution of the pumping optical density on the laser material, thereby affecting the uniformity, divergence and optical distortion of the output beam. . Both the working substance and the pump source are installed in the concentrating cavity, so the advantages and disadvantages of the concentrating cavity directly affect the efficiency and working performance of the pump.
4, Optical cavity
It consists of a total reflection mirror and a partial mirror, which is an important part of a solid-state laser. The optical cavity limits the direction and frequency of the oscillating beam to ensure high monochromaticity and high directivity of the output laser.
5, Cooling and filter system
Cooling and filtering systems are essential auxiliary devices for lasers. Solid-state lasers produce more severe thermal effects when operating, so cooling is usually required. Mainly to cool the laser working substance, pumping system and concentrating cavity to ensure the normal use of the laser and the protection of the equipment. The most widely used method is liquid cooling.
